Road-maintenance machine



' C. A. GUSTAFSON ROAD MAINTENANCE MACHINE Filed Feb. 231923 2 Sheets-Sheet 1 F/gj A 7" TOR/VF rs c. A. GUSTAFSON ROAD MAINTENANCE MACHINE Filed Feb. 23 1923 2 Sheets-Sheet 2 fiTTORNEYG Patented Get. 7, 1924.

CARL A. GUSTAFSON, OF MINNEAPOLIS, MINNESOTA, ASSIGNOR TO RUSSELL GRADER I MANUFACTURING 00., OF MINNEAPOLIS, MINNESOTA, A CORPORATION OF MINNE- SOTA.

ROAD-MAINTENANCE MACHINE.

Application filed February 23, 1923.' Serial No. 620,739.

T 0 all whom it may concern:

Be it known that I, CARL A. GUsTAFsoN, a citizen of the United States, residing in the city of Minneapolis, county of Hennepin, and State of Minnesota, have invented certain new and useful Improvements in Road-Maintenance Machines, of which the following is a specification.

This invention relates to improvements in road machines of the class designed particularly for use in maintaining a smooth surface upon a graveled road or other earth highway.

Owing to the steadily increasing amount of traflic over rural roads and highways, due to the increasing number of automobiles, etc., the problem of maintaining such roads in good condition is gradually becoming a most important one. To maintain a good road it is necessary that the road surface be kept smooth and hard andfree from any irregularities. This has hereto fore been accomplished, to a certain degree, by the employment of drags, scrapers, or other simple maintenance equipment, by the use of which a considerable amount of -manual labor has sometimes been required in order to attain the desired results.

However, more recent development in the art has resulted in the production of a road maintenance machine designed similarly to an ordinary road grader, but comparatively light in weight. In like manner, this machine comprises a curved blade adjustably mounted upon a frame'which is borne by four wheels. At present, the popular road maintenance system adopted in most localitiesthroughout the country, consists of the employment of one man, whose duties are, to patrol a certain section of a road or highway, to maintain such road in good condition. Machines for this purpose are therefore preferably operable by one man and are usually drawn by a team of horses, although they may be propelled by any other source of motive power, if desired.

When using the above described machine, considerable difiiculty is sometimes experienced in producing a smooth surface upon a road orhighway, especially if the road surface is hard and dry. This difficulty is caused by loose joints and pivots in the blade supporting means, allowing having to provide ample clearance in all movable joints and pivots toinsure free movement of thesame, and also to facilitate assembling. It is also impractical to provide closely fitted joints in machines designed for this purpose due to the increased cost in manufacturing.

Therefore, due to the above described method of supporting the blade, it will be readily seen that as the blade passes over the road surface, while in contact therewith, it will be free to move up and down within the limit of the clearance or looseness provided in the blade supporting means. Thus the blade will follow, to a certain degree, the contour of the. road surface, tending to rise when engaging a high spot in the road surface and lowering when passing over a low spot, resulting in the impossibility of providing or maintaining a smooth surface, especially if the road or highway is hard and dry. v

The primary object of this invention is to provide in a machine of the class above described, means for positively preventing the blade from chattering or moving loosely up and down when in contact with the road surface. By the employment of this novel feature in a road maintenance machine, the above slack or looseness in the blade supporting means will be entirely eliminated, and the blade will be securely held relative to the main frame of the machine, although capable of the usual adjustments provided in machines for this purpose. Thus, when the blade engages a high spot or mound in the road surface it will be prevented is to provide an improved road maintenance machine.

Other objects of the invention will more fully appear from the following detailed description and the accompanying drawings, and will be pointed out in the annexed claims. 1

In the drawings there has been disclosed a structure designed to carry out the objects of the invention but it is to be understood that the invention is not confined to the exact features shown, as various changes may be madewithin the scope of the claims which follow.

In thedrawings:

Figure 1 is a view in side elevation of a road maintenance machine, showing my invention applied thereto;

Figure 2 is a transverse sectional view, on the line 2-2 of Figure 1; showing the takeup means connected to the blade and the centershift bar of the machine;

Figure 3 is a detail sectional view on the line 33 of Figure 2, showing the method of mounting the spring supporting bracket upon the centershift bar, and

Figure 4 is a front View of Figure 3.

Broadly, the invention consists of mounting a heavy coiled tension spring between the blade of the machine and the usual cross member or centershift bar of the main frame, having its lower end. secured to. the blade and its upper end to the bar. The function of this spring is to take up the usual play or slackness prevalent in the blade supporting means, by imparting an upward force to the blade.

In the selected embodiment of the invention here shown, there is illustrated a road maintenance machine, of usual construction, comprising a main frame 11, draw bar frame 12, the usual circular blade supporting frame 13, curved blade 14, and front and rear wheels 15 and 16. The blade adjusting means,.as shown in the drawings,

consists of the usual hand wheels 17, lifting shafts 18 and connecting rods 19. The lifting shafts are connected to the hand wheels by means of a worm and gear'21.

As is shown in Figure 2 of the drawings, a small bracket 21 is secured to the rear side of the blade at its lower middle portion, preferably, by means of a bolt 22. This bracket is apertured to receive one end of a. coiled tension spring 23, connected thereto by means of the hook 24: of the spring. The opposite end of the spring is provided with asimilar hook 25, adapted to receive one end of a suitable chain 26. The upper end of the chain isadjustably connected to the depending end portion 27 of a suitable spring supporting bracket 28, adj ustably and removably mounted upon the usual cross mem fiber or centershift bar 29 of the main frame The depending end portion 27 of the bracket 28 is preferably provided with an aperture 31 of suitable size to permit the links of the chain 26 to pass therethrough. (Figure TL.) An open ended slot 32, connecting with the aperture 31, extends down' wardly therefrom and is adapted to receive any one of the links of the chain by means of which the upper end of the chain may be securely connected to the supporting bracket 28. By this simple method of securing the chain to the bracket, the tension of the spring may be readily adjusted as desired by merely lifting the chain out of the slot 32 and passing it either one way or the other until the desired tension is attained. To make the above adjustment the blade may be raised by means of the hand wheels 17 until the chain becomes slack.

It is common in road machines designed for this purpose to have the blade mounted in such a manner as to be capable of lateral adjustment. This is accomplished by means of the usual centershift block 33, slidably mounted upon the bar 29 and secured thereto by means of the bolt orpin 34. The usual connecting rod or bar 35 connects the block 33 with the cross member 36 of the draw bar frame. A plurality of apertures 37 are provided in the centershift bar for the adjustment of the block 33 thereon.

Means are therefore provided whereby the spring supporting bracket 28 may be removed from the bar 29, when it is desired to shift the centershift block 33 from one side u to the other for the lateral adjustment of the blade. An'integral lug' 38 is provided upon the bracket 28 and projects outwardly therefrom beneath the lower edge of the centershift bar 29. This lug is adapted to receive the lower terminal end of a suitable latch 39, slidably mounted upon a suitable rivet or bolt 41 secured to the upper portion ofthe bracket 28 by means of an elongated aperture or slot 40. The upper portion of this bracket is preferably formed with an integral boss 42 adapted to overhang the upper edge ofthe bar 29, as indicated in Figure 3. This provides a very rugged and substantial means for supporting the upper end of the chain 26, carrying the spring 23.

When it is found necessary to remove the bracket 28 from the bar 29 for the adjustment of the blade, the latch 39 will be disengaged from the lug 38 and moved to a horizontal position. When in this postiion the bracket may be readily removed from the bar and the block 33 adjusted to the desired postiion. 1

Thus, by the employment of the novel take-up means shown in this invention, the

blade will be firmly held in its supporting means. The spring 23 may also function as a means for counterbalancing the weight of the bladeand the draw bar frame. Battling" iae rec

o combination of a frame, a blade and means for supporting it from said frame, with means for eliminating lost motion in said blade supporting means.

2. In a road maintenance machine, the combination of a frame, a scraping blade and supporting means therefor, and means having a direct connection with said blade for yieldingly connecting it with said frame to exert a lifting force on said blade and take up lost motion in the connections thereof.

3. In a road maintenance machine, the combination of a frame, a scraping blade and means adapted to sup-port it upon said frame, with means yieldingly connecting said blade to said frame and exerting a lifting force thereon.

4. In a road maintenance machine, the combination of a frame, a blade and support-ing means therefor, with a coiled extension spring having one end connected'to said blade and means connecting the other end of said spring to said frame.

5. In a road machine, the combination of a frame, a scraping blade and supporting means therefor, with a spring having one end connected to said blade and flexible means connecting said spring to said frame.

6. In a road machine, the combination of a frame, a scraping blade and supporting means therefor, with a spring having one end connected to said blade, adjusting means mounted on said frame, and flexible means connecting said spring. to said ad justinlg means.

. 7. e combination with a grading machine frame, of a scraper blade supported therein, a coiled spring having one end connected to said blade, a bracket carried by said frame, andflexible means connectin said bracket with the other end bf sai spring.

8. he combination with a grading machine frame, of a scraper blade supported therein, a coiled spring having one end connected to said blade, an adjustable removable bracket carried by said frame, and flexible means connecting said bracket with the other end of said spring. I

9. The combination with a grading machine frame, of a scraper blade, means supporting it in said frame, and means preventing vertical movement of said blade as it passes into or out of contact with the work.

10. The combination with a grading machine frame having a center shift bar, of a scraper blade supported in said frame, a bracket adjustably supported on said bar and having a slotted lower end, a coiled spring having one end connected to said bladeand a chain attached to the other end of said sprin and having links to enter the slot in said bracket, said spring normally exerting an upward lifting force on said blade and taking up lost motion in the connections between said blade and frame.

In witness whereof, I have hereunto set my hand this 20th day of February, 1923.

CARL A. GUSTAFSON. 

